This invention relates to a system for removing and replacing liquid from and into a reservoir such as a radiator for an internal combustion engine. The liquid is stored in a tank from which it may subsequently be transferred back into the reservoir.
More particularly, the invention relates to an improved system, where the device for coupling a conduit or transfer hose to the reservoir has a double shut-off capability so that the process of connecting or disconnecting the conduit to or from the reservoir does not result in the escape of liquid from either the reservoir or the conduit.
The invention is particularly useful in connection with the method and apparatus shown and described in my U.S. Pat. No. 5,242,273. That system includes a storage tank and a conduit connected at a point near the bottom of the tank. The tank is also connected to an air system with means to either evacuate air from the tank or to pressurize the tank. This may be accomplished by an air pressure system normally found in vehicle service facilities.
The pressure available is used directly to pressurize the interior of the tank. To evacuate air from the tank, however, a venturi device is used and the air pressure system is connected in such a way as to provide high velocity flow through a venturi throat. The pressure drop that occurs in the venturi throat is then tapped and connected through a conduit to evacuate air from the tank.
The other end of the liquid conduit is connectable to the reservoir at a point as low as possible in the reservoir.
To extract the liquid coolant from the reservoir, the tank is first evacuated using the venturi system and then sealed to maintain a vacuum within the tank. Then the conduit is connected in such a way that the liquid is drawn from the reservoir into the tank. The extraction is continued until the liquid is entirely removed or until pressure equilibrium is reached within the tank.
To inject liquid coolant into the reservoir, pressure is applied directly to the tank and the conduit is appropriately connected so that the liquid coolant in the tank is forced into the reservoir.
One difficulty encountered in connection with the system thus described, is that of completing the necessary connections between the storage tank and the liquid coolant reservoir. This process typically involves the opening and closing of valves and the connection of the conduit to the reservoir at a suitable location well below the normal liquid level (normally an awkward location).
One technique is to provide a nipple or other device that is capable of quick connection to a cooperating connector on the liquid conduit. This results in a simpler and more efficient connection, however, during the connection and disconnection process, liquid coolant may escape through one or both of the respective connectors. The loss of liquid coolant in this way can be a serious disadvantage particularly when the purpose is to avoid the environmental pollution resulting from a liquid contaminant entering a floor drain or the like.
The device of the present invention minimizes and may entirely eliminate the difficulty described above and affords other features and advantages heretofore not obtainable.